Not applicable.
Not applicable.
The embodiments of the present invention generally relate to theatrical lighting systems that are digitally controlled and to the theatrical ellipsoidal spotlights used therein. More specifically, the embodiments of the present invention relate to color changing apparatus for theatrical ellipsoidal spotlights.
Lighting systems are typically formed by interconnecting, via a communications system, a plurality of lighting fixtures and providing for operator control of the plurality of lighting fixtures from a central controller. Such lighting systems may contain theatrical ellipsoidal spotlights. Applications and events in which theatrical ellipsoidal spotlights are used to great advantage include showrooms, television lighting, stage lighting, architectural lighting, live concerts, and theme parks.
Prior to the advent of relatively small commercial digital computers, remote control of light fixtures from a central controller was done with either a high voltage or low voltage current; see, e.g., U.S. Pat. No. 3,706,914, issued Dec. 19, 1972 to Van Buren, and U.S. Pat. No. 3,898,643, issued Aug. 5, 1975 to Ettlinger, both of which are incorporated by reference herein for all purposes. With the widespread use of computers, digital serial communication was widely adopted as a way to achieve remote control; see, e.g., U.S. Pat. No. 4,095,139, issued Jun. 13, 1978 to Symonds et al., and U.S. Pat. No. 4,697,227, issued Sept. 29, 1987 to Callahan, both of which are incorporated by reference herein for all purposes. In 1986, the United States Institute of Theatre Technology (xe2x80x9cUSITTxe2x80x9d) developed a digital communications system protocol for theatrical lighting known as DMX.
A theatrical lighting system may include a central controller that uses the DMX protocol to communicate over a communication system to a plurality of dimming units. Each dimming unit may have a plurality of controlled outputs with each output being electrically connected to the lamp of an ellipsoidal spotlight. A single dimming unit may control the intensity of 4 or more of the ellipsoidal spotlights. For some shows, as many as 100 ellipsoidal spotlights connected to 25 dimming units may have their intensity individually controlled by an operator of the central controller. The operator of the central controller inputs address and command information that is sent over the communications system to individually control the intensity of each of the plurality of ellipsoidal spotlights.
For many theatrical shows, colored lighting is required to provide a dynamic effect on the stage. Most ellipsoidal spotlights have a mounting location for a color filter located in front of the final lens. The mounting location is commonly referred to as a gel holder. The term gel comes from the gelatin substrate sometimes used to manufacture color filters. Gels today may be constructed of polycarbonate flexible sheeting to help resist the high temperatures associated with the light energy projected from the ellipsoidal spotlight. A sheet of colored gel may be held in a frame, which may be located or fixed relative to the gel holder of the ellipsoidal spotlight. Even though the gels may be constructed of polycarbonate, the light energy from the colors not transmitted by the gels is absorbed by the gels, thus elevating the temperature of the gel. Therefore, the gels must be changed frequently by show maintenance personnel because the gel color fades or the sheeting distorts due to the high heat absorbed by the gel. The labor costs to change the gels frequently for large shows can be quite high.
Color scrolling devices have been manufactured in order to allow remote controlled selection of a desired gel color for a particular spotlight by an operator of the central controller. The color scroller device often includes one or more scrolling rolls of gel sheeting, where each of the rolls of gel can be remotely controlled to scroll through the length of gel sheeting. One exemplary gel scrolling system using multiple scrolls or variable saturation is disclosed in U.S. Pat. No. 5,126,886 to Richardson, et al and is incorporated by reference herein for all purposes.
The gel scrolling system disclosed by Richardson is an improvement over the prior art color changing gel scrollers because it uses multiple gel scrolls each of a different color and each with variable saturation. Thus, the operator of the central controller may gradually change a first color to a second color by varying the saturation of the multiple gel scrolls in front of the ellipsoidal spotlight. The gel used in the Richardson gel scroller still has the disadvantage of fading and distorting over time and maintenance is again required to apply new gel material to the scrolls.
One popular theatrical ellipsoidal spotlight model is the Source Four(trademark) as manufactured by Electronic Theatre Controls of Middleton, Wis. The Source Four(trademark) ellipsoidal spotlight has a modular construction so that various lens systems can easily be applied to suit the application of a particular show. The Source Four(trademark) ellipsoidal spotlight is constructed of a reflector housing assembly and front barrel assembly that may include a lens tube assembly. These assemblies are easily disassembled and reassembled in that the reflector assembly can be disconnected from the front barrel assembly and the lens tube assembly can be removed from the front barrel assembly.
Therefore, it is possible to produce a modular, housing-based optical system that can be designed to mate with the reflector assembly and the front barrel assembly of the Source Four(trademark) spotlight. At least one company has built a modular optical apparatus that mates the reflector assembly with the front barrel assembly of an ellipsoidal spotlight. The Great American Market Company of Hollywood, Calif. has produced a product called an SX4(copyright) that may be used to automatically change or scroll patterns in the light path and is installed between the reflector assembly and the front barrel assembly of a Source Four(trademark) ellipsoidal spotlight.
There is need for an improved color changing apparatus to be used in conjunction with a conventional theatrical ellipsoidal spotlight and that does not possess the drawback of incorporating gel color filters that fade or distort and yet can produce a broad range of varying color.
The embodiments of the present invention include a color changing apparatus adapted to be installed between the reflector assembly and front barrel assembly of a theatrical ellipsoidal spotlight. The color changing apparatus includes a housing for connecting to the spotlight components. Contained within the housing are a plurality of color filters, preferably dichroic color filters, serially arranged perpendicular to the light path. The color filters may include constant or variable density patterns of any desirable color and are transported into the light path to effect a change in lighting conditions. The color changing apparatus is also preferably equipped with a control system enabling remote actuation and control of the system.
One embodiment includes a color changing apparatus for a theatrical ellipsoidal spotlight having a reflector housing and a front barrel housing. The color changing apparatus has a housing with first and second sides, a first fastening system, for releasably joining the first side of the housing to the reflector housing, and a second fastening system, for releasably joining the second side of the housing to the front barrel housing. A plurality of color filters, preferably dichroic color filters, is contained at least in part within the housing. In certain embodiments, the color filters are serially arranged, include filters that are cyan, magenta, and yellow, and may be transported by an actuator to be into or out of a light path that is created by the reflector of the ellipsoidal spotlight.
In another embodiment, the color changing apparatus for a theatrical ellipsoidal spotlight includes a housing joining a reflector housing and a front barrel housing of the theatrical ellipsoidal spotlight. Light is projected along a path from the reflector, through said housing and through the front barrel. A plurality of dichroic color filters are disposed within the housing and at least one of said plurality of dichroic filters has a variable density pattern. The apparatus also has a control system including a plurality of actuators and a communications port, wherein the control system is adapted to adjust the position of the plurality of dichroic filters. The communications port receives a command and the control system acts on the command to control the actuators so as to transport selected dichroic filters into the light path. The communications port may be connected to at least one external connector adapted to relay both power and communications.
In another alternative embodiment, a theatrical lighting system includes two theatrical ellipsoidal spotlights, each containing a pattern gate, a color changing apparatus, a reflector housing, and a front barrel housing. The color changing apparatus are conjoined with reflector housings and the front barrel housings of the ellipsoidal spotlights. The color changing apparatus comprise a plurality of dichroic filters serially arranged between the reflector housing and the front barrel housing. Each color changing apparatus includes a control system connected to the first color changing apparatus by a communications port adapted to receive a command signal to cause the plurality of dichroic filters to be transported into a light path created by the reflector housing of the theatrical spotlight.
Another embodiment includes a method for projecting light on a surface by providing a plurality of color filters disposed within a housing, installing the housing in a theatrical ellipsoidal spotlight comprising a pattern gate, between a reflector housing and a front barrel housing, to form a light path that runs from the reflector, through the housing, and into the front barrel, and projecting light from the reflector along the light path and onto the surface.
An alternative embodiment includes a method for controlling light projected onto a surface by providing a plurality of color filters disposed within a housing that is installed between a reflector housing and a front barrel housing of a theatrical ellipsoidal spotlight establishing a light path that runs from the reflector, through the housing, and into the front barrel, connecting a plurality of actuators to the plurality of color filters, wherein the plurality of actuators are adapted to transport each of said plurality of color filters into and out of the light path, and transmitting a command to the control system causing one of the plurality of actuators to transport one of the plurality of color filters into the light path.
Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior art theatrical ellipsoidal spotlights. The various characteristics described above, as well as other features, objects, and advantages, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.